Common symptoms
A thump or delay when selecting drive or reverse, revs flaring between gears, harsh or late shifts, a gear warning light, or the car stuck in one gear (limp mode).
Fluid first
Low, old or burnt transmission fluid causes many shifting complaints. Some gearboxes have no dipstick and need checking on a hoist. Note any red or brown fluid under the car.
Electronic faults
Modern automatics are computer controlled. A faulty sensor, solenoid or wiring fault can cause poor shifting and limp mode, and a diagnostic scan is the right first step.
CVT gearboxes
Many late-model Japanese imports use a CVT. Shudder, whining or a rubber-band feeling under acceleration are typical CVT complaints and need someone familiar with them.
What to tell the mechanic
Make, model and year, the symptoms and when they happen (cold, hot, uphill), any warning lights, and when the fluid was last changed.
Safe to drive?
If the car is stuck in one gear, slipping badly or the warning light is flashing, drive gently to a booking or arrange a tow. Continuing to drive can turn a small repair into a rebuild.
General guidance only, not a diagnosis. If in doubt, do not drive it and have it inspected. In an emergency, call 111.
Who can help
Get quotes for transmission & clutch repair near you
Questions
Should I just change the fluid?
Sometimes it helps, but on a gearbox that has never had a change, ask the mechanic first. Diagnose before you spend.
What should I put in the job?
The symptoms, the kilometres, whether it is a CVT if you know, and any codes from a scan.